The present invention relates to the scheduling of movement of plural units through a complex movement defining system, and in the embodiment disclosed, to the scheduling of the movement of freight trains over a railroad system, and particularly to an interface between a line of road movement planner and a yard movement planner.
Systems and methods for scheduling the movement of trains over a rail network have been described in U.S. Pat. Nos. 6,154,735, 5,794,172, and 5,623,413, the disclosure of which is hereby incorporated by reference.
As disclosed in the referenced patents and applications, the complete disclosure of which is hereby incorporated herein by reference, railroads consist of three primary components (1) a rail infrastructure, including track, switches, a communications system and a control system; (2) rolling stock, including locomotives and cars; and, (3) personnel (or crew) that operate and maintain the railway. Generally, each of these components are employed by the use of a high level schedule which assigns people, locomotives, and cars to the various sections of track and allows them to move over that track in a manner that avoids collisions and permits the railway system to deliver goods to various destinations.
As disclosed in the referenced applications, a precision control system includes the use of an optimizing scheduler that will schedule all aspects of the rail system, taking into account the laws of physics, the policies of the railroad, the work rules of the personnel, the actual contractual terms of the contracts to the various customers and any boundary conditions or constraints which govern the possible solution or schedule such as passenger traffic, hours of operation of some of the facilities, track maintenance, work rules, etc. The combination of boundary conditions together with a figure of merit for each activity will result in a schedule which maximizes some figure of merit such as overall system cost.
As disclosed in the referenced applications, and upon determining a schedule, a movement plan may be created using the very fine grain structure necessary to actually control the movement of the train. Such fine grain structure may include assignment of personnel by name as well as the assignment of specific locomotives by number and may include the determination of the precise time or distance over time for the movement of the trains across the rail network and all the details of train handling, power levels, curves, grades, track topography, wind and weather conditions. This movement plan may be used to guide the manual dispatching of trains and controlling of track forces, or provided to the locomotives so that it can be implemented by the engineer or automatically by switchable actuation on the locomotive.
The planning system is hierarchical in nature in which the problem is abstracted to a relatively high level for the initial optimization process, and then the resulting course solution is mapped to a less abstract lower level for further optimization. Statistical processing is used at all levels to minimize the total computational load, making the overall process computationally feasible to implement. An expert system is used as a manager over these processes, and the expert system is also the tool by which various boundary conditions and constraints for the solution set are established. The use of an expert system in this capacity permits the user to supply the rules to be placed in the solution process.
Currently, a dispatcher's view of the controlled railroad territory can be considered myopic. Dispatchers view and processes information only within their own control territories and have little or no insight into the operation of adjoining territories, or the railroad network as a whole. Current dispatch systems simply implement controls as a result of the individual dispatcher's decisions on small portions of the railroad network and the dispatchers are expected to resolve conflicts between movements of objects on the track (e.g. trains, maintenance vehicles, survey vehicles, etc.) and the available track resource limitations (e.g. limited number of tracks, tracks out of service, consideration of safety of maintenance crews near active tracks) as they occur, with little advanced insight or warning.
The problem is particularly severe where the territories differ significantly in function. For example, terminals or yards exist with a number of receiving tracks or leads and a number of departure tracks or leads. Multiple car trains arrive on various receiving leads and are broken up and reformed into multiple car trains of departure leads. Coordination between the line-or-road dispatcher and the yardmaster to insure that an incoming train is received on a receiving line with access to the appropriate yard for the reconfiguration of the train. Likewise, the line-of-road dispatcher must know the departure line in order to plan the movement of the train after it leaves the yard.
As disclosed in the referenced applications, movement planners are available for planning the movement of trains within the various territories. Where one territory is a yard or a terminal, the line-of-road planning for the areas outside of the yard or terminal was necessarily independent of the planning for the terminal.
The movement planner for the line-of-road and the yard have been completely independent with communication between the yard master and the dispatcher typically accomplished on an ad hoc basis using radio or telephone as an issue arose. Such communication does not allow for sufficient coordination between the planned movement of the cars in the yard and the planned movement of the trains in the line of road to optimize the movement of the trains through the railway network.
Moreover, the yardmaster's movement plan is based on scheduled arrival and departure times, and updated information is generally not communicated to the yardmaster as the trains approach the terminal and often require significant revision. As a result, the use of yard resources has been inefficient. Likewise, the first accurate indication as to when a train is to be released to a line-of-road dispatcher is generally a telephone call from the yardmaster indicating that the train has been assembled and is ready for departure. Inefficiencies result from the change in the assignment of resources as is required by any departure from the anticipated departure time.
More importantly, information line-of-road dispatchers deliver trains to a terminal without regard to terminal capacity, car connection requirements or congestion within the yard, and are generally evaluated on the speed with which trains are moved across the line-of-road. As a result, trains are often delivered to congested terminals by line-of-road dispatchers resulting in increased congestion and exacerbating the yardmaster's problems in reconfiguring the trains. A delay in the delivery of the train to the terminal may permit the yardmaster to operate more efficiently within the yard and improve overall system efficiency. This delay may also permit the use of road resources by other trains increasing the throughput of the system.
Yardmasters are evaluated on the basis of the speed of assembly of trains within the yard without regard to road conditions or congestion, and often assemble trains for delivery to the line-of-road dispatcher without regard to the congestion of the road, exacerbating the dispatcher's problems in moving the trains. A delay in the delivery of a newly constructed train to the line-of-road may permit the line-of-road dispatcher to operate more efficiently and improve overall system efficiency. Knowing that little is gained by rushing the assembly of a particular train, the yardmaster may assign yard resources to other trains increasing the efficiency of the yard and the throughput of the system. In such a situation, a high value car may not get priority in the yard if the line-of-road exiting the terminal is congested.
It is accordingly an object of the present invention to increase the coordination between the line-of-road and terminal planning systems through electronic connection, reducing voice communications and obviating the interruption of the respective dispatchers. The electronic connection of the movement planners results in continuously updated information and improved planning for both line-of-road and yard movement of trains, increasing the profitability of the overall transportation system.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.